Reciprocating pumps



July 31, 1956 c. w. MEADER RECIPROCATING PUMPS 2 Sheets-Shee 1 Filed Feb. 17, 1953 mana-f July 31, 1956 c. w. MEADER 2,756,679

REC IPROCATING PUMPS Filed Feb. 17, 195s` 2 sheets-sheet 2 /2/ nl; 20 15 /5IZ 5 122` ,0

/6/ Pkt 5 Z3 9 /7 United States Claims priority, application Great Britain February 18, 1952 6 Claims. (Cl. 10S- 48) This invention relates to reciprocating pumps capable of use for pumping thick semi-liquid substances, small solid materials and similar bodies. It is concerned with a pump which compri-ses a khollow cylinder having an open end the rim of which is operative on axial movement of the cylinder to advance or cut into a mass or body of material to be pumped so that the cylinder takes up a charge of the material, a piston movable within the cylinder and operative to expel the charge from said open end and to deliver it through a discharge aperture of the pump, and means operative thereafter to withdraw the cylinder and piston for afresh operation.

An object of the present invention is to provide an improved construction of pump which is capable of being lowered into a mass or body of thick semi-liquid substance, small solid material, or' the like, to be pumped and which enables a freer flow of such bodies to the cylinder to be obtained.

According to this invention, the improved construction of pump is characterised in that it comprises a rst part in which the open-ended cylinder is mounted to partake of axial movement to a projected position -to take up a charge of material to be pumped, a second part in which rthe discharge aperture of the pump is situated, and means in the form of a skeleton or open-sided structure, such as a set of pillars for mounting the second part upon but at a distance from the lirst part and so lthat, when the open-ended cylinder is withdrawn after a charge of material has been expelled from it by the piston, the pump body is substantially freely open around the axis of the cylinder between said first and second parts.

In order to enable the invention to be readily understood, reference is directed to the accompanying drawings wherein:

Figure l is a sectional elevation of one example of the improved pump,

Figure 2 is a section on the line II-II of Figure l,

Figure 3 is a view similar to Figure l showing another example of the pump,

Figure 4 is a sectional View to a larger scale illustrating part of the construction of Figure 3,

Figure 5 is a fragmentary sectional a further example of the pump,

Figure 6 is a view similar to Figure 4 of part of the construction of Figure 5, and

Figure 7 is a View similar to Figures land 3 illustrating a further example of the pump of the invention.

In Figures land 2, the iirst part 1 of the pump has the second part 2 mounted on it by a skeleton or opensided structure in the form of a set of pillars 3. As shown by Figure 2, there may suitably be three of the pillars view illustrative of atent 3 in the set spaced 120 apart about the axis of the openl ended cylinder 4 and parallel thereto. The rst pump part 1 suitably embodies a cylinder 5 coaxial with and of larger diameter than the open-ended cylinder 4. In this second cylinder is a piston 6 to which the openended cylinder 4 is rigidly secured at its end opposite the open end. The open-ended cylinder is mov-able in rfice a bearing 7 at one end of 'the second cylinder 5 which at this end is flanged at 8 tov take one end of the pillars 3 which are bolted in holes in the ilange. The pillars also pass through holes in and secure a closure 9 for the adjacent end of the cylinder 5. The second pump part 2 comprises a plate 10 in which the discharge aperture 11 of the pump is situated. This aperture 11 is of slightly less diameter than the open-ended cylinder 4. The plate 10 is bolted to the other end of the pillars 3, the distance between the plate and the-closure 9 of the second cylinder aforesaid suitably being determined by llanges or shoulders 12 on thel pillars 3 at their ends, packing discs 13 'being interposed if desired. Said plate 10, and closure 9 are parallel to each other and the distance between them is preferably made equal to the stroke of the open-ended cylinder 4 in its axial movement. Adjustment to attain this distance is possible by using packing discs 13 of diiterent thicknesses. The rim of the cylinder 4 at the open-end thereof is adapted, when such cylinder is projected from the iirst pump part 1 to seat on a xed annular seating 14 disposed on the second pump part about and co-axial with the discharge aperture 11. In the second cylinder 5, and disposed on the opposite side of the piston 6 to the open-ended cylinder 4, is a second .piston 15 which is connected by a piston rod 16 rigidly with a third piston 17 disposed in the open-ended cylinder. In the position shown in Figure l the rst piston 6 is spaced from the bearing 7 by stops 18. In addition, the lirst and second pistons 6, 15 are spaced apart in their closest positions, also shown in Figure l, by a spacer 19 fitted to the second piston. These pistons 6, 15 are operatedin the second cylinder by fluid pressure which may be pneumatic or hydraulic. Suitable inlet and exhaust connections 2i) to 23 for the duid pressure are provided on this cylinder as will be described.

ln operation the pump, with the open-ended cylinder 4 and the third piston 17 retracted (cf. Figure 7), is lowered into the material to be pumped and, because the pump, except for the columns 3 which are of relatively small diameter, will be open all around the 4axis of the open-ended cylinder, the space between the iirst and second pump parts 1, 2 aforesaid is able to become readily filled with the material. The open-ended cylinder 4, having been withdrawn by uid pressure applied to one side of the piston 6, through the inlet 2i), is projected by uid pressure .applied to the other side of that piston through the inlet 21 (cf. Figure 7), to take up a charge of material within it. In this operation exhaust of duid pressure from the first side takes place through 20. The rim of the open end of the cylinder 4 at this time advances or cuts through the material in the said space so that such material enters the open end as will be understood. After the piston 6 reaches the stops 18, i. e. when the open end of cylinder 4 appropriately engages the annular Vseating 14 about the discharge aperture 1-1 in the second pump part 2, the second piston 15, which also has been previously withdrawn (having been pushed back by the first piston, cf. Figure 7), is operated by duid pressure, applied to it through the inlet 22, in the opposite sense to cause the third piston 17 to expel the charge of material, taken up by the open-ended cylinder 4, through the discharge aperture 11 to delivery. In this operation, exhaust of fluid pressure fromthe cylinder 5 takes place at 23. The delivery from 11 is suitably through a short delivery pipe 24 carried by the second pump part and past a non-return valve (not shown) at the forward end of that pipe.

The operation of the pistons and of the open-ended cylinder is Similar to that described in the speciication belonging to my patent application Serial No. 154,921, led April l0, 1950, now Patent No. 2,667,841.

In the operation, as soon as the open-ended cylinder 4 .3 is again withdrawn, (exhaust from 5 then taking place through 22), the material is able substantially freely to fill up the space which this `.cylinder previously occupied in its proieetedfpositionso thaton the next operation of the cylinder 21jfresh -charge of the material is `efficiently takenmp, and S on.

It is not essential to use the above lannular -seating 14 on-the second pump part 2 for the open end of the openended cylinder. In other examples of the pump of the invention the construction is such that the cylinder is received at its -open end within a discharge aperture in the second pump part. I n one such example, which is illustrated in Figures 3 and 4, the discharge aperture 11 is surrounded by-an internally taperpart 25 yof the short delivery pipe 24, and the open end of the open-ended cylinder 4 has a corresponding external taper, see Figu re 4. This taper may seat in the taper of the short delivery pipe 24, or, kas shown, the arrangement may be such thatgit ,does not actually seat itself so as to prevent lsolid material from presenting an obstruction between that end of the cylinder 4 and the aforesaid internally taper-apart. The outward-stroke of the open-ended cylinder in the latter case may be determined by stops, such as 1,8, operative on the first piston 6 as aforesaid. In another example, shown in Figures 5 and 6, the discharge aperture 11is made large enough to accommodate va sealing leather or -hard rubber ring 26. The latter is of L shape in section and is clamped in position between the plate and a ring 27, see Figure 6. At the end of its outward stro-ke the open-end of the open-ended cylinder 4 slides `into the part 28 of the sealing ring corresponding to the bottom of the L, until the piston of this cylinder meets stops of the nature aforesaid. The remainder (not Shown) of .the pump illustrated in Figure 5 may be lsimilar to Figure v3. As will berealised the open end of the openended cylinder 4 in Figures 5 and 6 is not only received within the discharge aperture 11 but also is sealed therein. In this construction, the open-ended cylinder is shown of uniform diameter but internally taper at its open end. rIfhis tapering, also the external tapering in Figures 3 and 4, provides a relatively sharp edge to enable the cylinder 4 the easier to cut its way `through material to be pumped. 'I hese internal and external taperings of the open-ended cylinder, however, are not essential. lf there were no external tapering .at the Open and of the .Cylinder in Figures 3 and .4, the kcylinder could have line contact with the internally taper -part 25. Parts shown in Figures 3 and 5, which are similar to partsv shown in Figure l aresimilarly lnumbered for reference purposes. The examples shown in Figures 3 to 6 embody features similar to and possessing advantages described in the specification belonging to -my concurrent patent application Serial No. 337,412 of even date herewith.

According to Figure 7, a series or a ring of comparatively large holes 30 kmay be formed through the first piston 6 over that region lying within the circumference of the cylinder 4. This -would enable the quantity of operating fluid required for carrying out the outward stroke of the piston 6 on the filling or cutting stroke of the open-ended cylinder 4 to be reduced, for example to only half the quantity which might otherwise be required as will be understood. In Figure 7, the stops 18 aforesaid are not usedbecause when the open end of the cylinder 4 comes against the seating 14 the latter acts in equivalent fashion. In other respects the construction shown in Figure l7 is substantially similar to that shown in Figure l and similar reference numerals are used in the two figures for reference purposes. It will be realised that holes of the nature of lthe holes 30 in Figure 7 may be used in the examples of pump shown in Figures 1 to 6.

The cycle of operations of the pump of the invention may be controlled from a single rotatable valve as will be understood by those skilled in the art. Alternatively, the cycle of operations may be controlled by means of piston type valves, there being one piston valve for each movement of the pump. The piston valves may be operated in sequence by means of contacts made on completion of each movement of the pump. The contacts may operate mechanically, electrically, pneumatically or hydraulically as will Ebe understood.

Whilst the open-ended cylinder and the charge-.expelling first piston therein yhave been above exemplified as being operated by fluid vpressure acting on respective pistons in the second cylinder, it will be -understood that alternatively, arrangement may be made for them to be operated mechanically or electrically. It will also be understood that provision may be made for their sequence of movements to be controlled mechanically or electrically.

VExamples of thick semi-liquid substances capable of being dealt with 4by the pump of the 'invention are mu'd, bauxite residues, 'paper pulps, sewage, sleech, cement s'lu'rries, unset concrete, o'il residues, filter cake, sludges, clays, silt, pastes and material prepared for the making of bricks, andan example of small solid materials Vis small coal.

'What I claim is:

l. In apparatus for pumping a mass of material, a first part, a second part secured to said first part and including a skeleton structure, said skeleton structure having a discharge aperture communicating therewith, a hollow cylinder mounted for axial movement in said first part and adapted to contact said material, a piston positioned in said cylinder and movable relative thereto for pumping said material through said cylinder, means for axially moving said hollow cylinder into said skeleton structure into contact with the material to be pumped and 'into communication with said discharge aperture, means for axially moving said piston yin said hollow cylinder for expelling said material through said discharge aperture, and Vmeans for retracting said cylinder and piston into said first part for repeating Vthe pumping operation.

2. In apparatus for pumping a mass of material as set forth in claim l, said 'second part including pillars joined to said first part, said pillars being spaced about .the longitudinal axis of said hollow cylinder and substantially parallel thereto.

3. In apparatus for .pumping a mass of material as set forth in claim l, said second part including a plate secured to `said skeleton structure, saidplate having a xed annular seat mounted thereon for receiving the end of said hollow cylinder.

4. In apparatus for pumping a mass of material as set forth in claim l, said second part including a plate, said discharge aperture being formed in said plate, whereby the end of said hollow cylinder in the discharge position contacts said plate and communicates with said discharge aperture.

5. In apparatus for pumping a mass of material as set forth in claim 4, said plate having a tapered opening formed therein defining said discharge aperture.

6. In apparatus for pumping a mass of material as set forth in claim 4, said plate having a sealing ring positioned thereon for-receiving the open end of said hollow cylinder in sealing relation therewith.

References Cited in the file of this patent UNITED STATES PATENTS 1,795,236 Schuif Mar. 3, 1931 

